LWN: Comments on "Running a mainline kernel on a cellphone"

Running a mainline kernel on a cellphone

speedster1 — Thu, 26 Nov 2015 06:35:23 +0000

> AIUI, freedreno has received some patches from Qualcomm via their Innovation Center (iirc), on the drm side of things.

That was a lucky misunderstanding -- their bosses thought they were contributing to improvements in Digital Rights Management ;)

Running a mainline kernel on a cellphone

BenHutchings — Tue, 24 Nov 2015 19:37:20 +0000

The 'ckt' is there to distinguish Canonical-maintained stable branches from those branches maintained or blessed by Greg K-H. It follows the same rules as other stable branches, though - without anything that's Ubuntu-specific or not upstream.

I'll be taking over maintenance of the 3.16 stable branch next year, likely changing 'ckt' to 'dkt'. (Certainly, it'll have to be something that sorts higher.)

Running a mainline kernel on a cellphone

jond — Tue, 24 Nov 2015 15:44:44 +0000

Expanding on this, looking at https://wiki.ubuntu.com/KernelTeam#Ubuntu_Platform_Kernel... , I don't recognise any names in Debian.

Running a mainline kernel on a cellphone

jond — Tue, 24 Nov 2015 15:42:16 +0000

Ben Hutchings doesn't.

Create a FOSS competitor running latest kernels

fithisux — Tue, 24 Nov 2015 13:41:55 +0000

This way, others will follow and require latest kernels. Even if it has less functionality and the price is right, people will follow. You just have to push latest kernels and advertise it.

Running a mainline kernel on a cellphone

Lennie — Tue, 24 Nov 2015 08:39:41 +0000

Did you know what ckt stands for ?: Canonical Kernel Team.

I assume basically everyone working on the Debian Kernel Team is employed by Canonical and works on both.

Running a mainline kernel on a cellphone

jospoortvliet — Mon, 23 Nov 2015 06:20:44 +0000

I agree - besides, there are technical ways google could push this. They don't seem to care, which is damaging their ecosystem - I guess it is ignorance more than anything. As usual with this stuff... It is hard to understand how a collaborative development model works and benefits participants.

silicon vendors are doing the kernel work

Hauke — Sun, 08 Nov 2015 09:22:35 +0000

I think the mainlining process has to start at the silicon vendors, they are doing all the kernel work and the device manufacturers only modify the work done by the silicon vendors a little bit.

In the home router market the silicon vendors provide an (old) kernel with support for their SoC and other chips, they sell or from third parties, connected to this main SoC. Some are also shipping a complete Linux distribution and provide reference PBC designs so the device manufacturers get a complete system which could get shipped to end consumers. These reference designs (software and hardware) are just copied and modified by the device manufacturers.

Mainline support for an SoC takes more time than bringing it somehow to work on some random (old) kernel. Most vendors wants to meet a short time to market and mostly the focus is only on the current silicon and not how one could save some work in the future for the next generation SoC, which uses similar IP cores or when a update of the kernel is needed.

Currently it looks like the big customers of the silicon vendors only want a somehow working kernel which supports all the features of the SoC, if these big costumers would say that they want upstream support for the SoC they would get it.

Running a mainline kernel on a cellphone

flussence — Fri, 06 Nov 2015 13:42:22 +0000

Moving from ARM to Intel just sweeps the problem under the rug and into the (massive, proprietary and encrypted) board firmware.

Running a mainline kernel on a cellphone

eean — Fri, 06 Nov 2015 04:22:29 +0000

How much of this is just the ARM ecosystem being so chaotic ? Like once we finally have Intel phones (?) I guess that will help.

Running a mainline kernel on a cellphone

Wol — Thu, 05 Nov 2015 11:06:27 +0000

> The reality is that it's counter productive to try to compel people to act against their own best interests.

The reality is that it's counter productive to try to compel people to act against their own PERCEIVED best interests.

And actually, the reality often is that you really are trying to force me to act against my own best interest. You're not me, you don't know what is or isn't important to me.

It's a lot harder to do, but if you can persuade someone that their best interests will be served by helping you, you then have a good basis for collaboration. Not only will they want to help you, but you will have a far better understanding of them.

Cheers,
Wol

Running a mainline kernel on a cellphone

liam — Tue, 03 Nov 2015 23:17:43 +0000

AIUI, freedreno has received some patches from Qualcomm via their Innovation Center (iirc), on the drm side of things.

Running a mainline kernel on a cellphone

spaetz — Tue, 03 Nov 2015 19:13:14 +0000

> Not 'Android release'. Android is free software so the vendors are free to do whatever the hell they want. Google's restrictions and controls are done through their app store and related software that runs on top of Android.

Not true. If you want to use (and sell) Android™ you need to abide by a whole lot of rules and preinstall priviledged services. Only in case you decide to skip to name Android (Amazon Kindle) you are free to do whatever the hell you want.

Running a mainline kernel on a cellphone

drag — Tue, 03 Nov 2015 14:21:08 +0000

Not 'Android release'. Android is free software so the vendors are free to do whatever the hell they want. Google's restrictions and controls are done through their app store and related software that runs on top of Android.

Google could indeed demand a specific kernel and it would gain a lot of traction like that, but it will weaken Google's position in the Android community. The more Google restricts it's partners then more expensive it becomes to partner with Google. The more expensive it is to follow Google's rules the more likely that somebody else to take over Google's 'benevolent rule' of Android (which would be much more 'friendly' in terms of proprietary driver encumbered kernels.). It's obviously contrary to Google's goals to make life more difficult for people that are willing to work with them then it needs to be.

The reality is that it's counter productive to try to compel people to act against their own best interests. You can't just 'force' people to be friendlier to the mainstream Linux kernel. How you win is by making it cheaper and easier to 'do the right thing' with the mainline kernel rather then chase down device-specific hacks/patches/kernels and closed drivers.

This has to come from a combination of improvements in the Linux kernel to make it more android friendly and participation of hardware chip set manufacturers to upstream their hardware support.

Running a mainline kernel on a cellphone

rahvin — Tue, 03 Nov 2015 00:26:15 +0000

There are all kinds of kernel bugs in every android release. That's just a simple fact. Most of root exploits are actually exploits of either the kernel or a privileged service running on top of it. We wouldn't be able to attain root without it.

Though better security would be a nice thing I doubt we'll see it unless the ARM phone chip guys embrace openness. Qualacom and others are openly hostile to openness.

Fining vendors? Perhaps it would work...

armijn — Sat, 31 Oct 2015 22:23:28 +0000

About half a year ago the senate in the Netherlands passed a law that puts a fine on keeping data breaches closed (Dutch only link): https://ictprivacyrecht.nl/beveiliging/wetswijziging-meld...

There is a maximum fine of 810,000 EUR. The EU is apparently working on similar laws. It is not directly aimed at security issues but data leaks are often a result of security issues (of any kind). So this might be a step into the right direction.

Running a mainline kernel on a cellphone

jospoortvliet — Sat, 31 Oct 2015 11:51:34 +0000

Google is important in any case. If the next Android release would simply require kernel 4.3, vendors would have no choice but to pressure their hardware vendors, who, in turn, would have to cave...

Running a mainline kernel on a cellphone

dlang — Sat, 31 Oct 2015 03:31:16 +0000

the fact that many people run vanilla kernels on such systems is an indication that in many/most cases the patches are not required (I did so for more than a decade at my last job)

A lot of the 'feature/driver' patches are actually backports of drivers or features that are in newer upstream releases.

Running a mainline kernel on a cellphone

marcH — Sat, 31 Oct 2015 03:09:54 +0000

The question is: how many of these patches are actually required for the system to be usable? I guess very few.

Running a mainline kernel on a cellphone

mtaht — Fri, 30 Oct 2015 19:22:44 +0000

We are doomed to a buggy future unless we can keep everything patched. I am sad to hear the handset market is entering the same dark pit of un-upgadeability - particularly in case of aging devices with new attacks present - that so many home routers have. Perhaps what we suggested here needs also apply to phones?

http://fossbytes.com/internet-inventor-vint-cerf-and-expe...

Running a mainline kernel on a cellphone

Karellen — Fri, 30 Oct 2015 18:56:23 +0000

Sorry, should have read the whole thread before commenting. keroami already mentioned the N900 further down earlier.

Running a mainline kernel on a cellphone

Karellen — Fri, 30 Oct 2015 18:54:11 +0000

The Neo900 project is doing something similar for the N900. And accepting donations.

http://neo900.org/

Running a mainline kernel on a cellphone

dos — Fri, 30 Oct 2015 17:25:11 +0000

Although I'm affiliated to Neo900 project, I'd like to keep the facts straight: it's the GTA04 project that works on kernel development and tries to keep it as close to upstream as possible. Then devices like Neo900, Pyra, lately also OpenPandora and BeagleBoard, and of course GTA04 itself (Letux devices) benefit from the work made on the GTA04 kernel :)

Running a mainline kernel on a cellphone

robher — Fri, 30 Oct 2015 16:54:36 +0000

ACPI on ARM is only for servers. No one else is looking to move from DT that I am aware of. Many phones have 3.4 kernels and are not even using DT.

Running a mainline kernel on a cellphone

ballombe — Fri, 30 Oct 2015 16:37:05 +0000

backports are not a problem since you can only backport something which is is mainline already.

Running a mainline kernel on a cellphone

tbird20d — Fri, 30 Oct 2015 16:34:12 +0000

I gave a lightning talk the next day, with more details on where the problem areas are. Linaro and the Linux Foundation have a joint project to work on some issues, but we can use lots of help. I'm maintaining a page of technical projects at: http://elinux.org/Kernel_areas_of_focus_for_mainlining. Please feel free to add notes about technical items for things out-of-tree on SoCs you're familiar with. Please drop me an e-mail (tim dot bird @ sonymobile dot com) if you are working on, or plan to work on, any of the areas on that page.

The main web page for the project (which covers more than just technical issues) is here:
http://elinux.org/CE_Workgroup_Device_Mainlining_Project

Running a mainline kernel on a cellphone

jpfrancois — Fri, 30 Oct 2015 12:42:50 +0000

I don't think ACPI or DT will change something here.
When boardfile where in use, they were not that big. I think the out of tree code is mainly drivers and random hacks to the scheduler / PM code.

Running a mainline kernel on a cellphone

tao — Fri, 30 Oct 2015 12:28:40 +0000

It's indeed a cool project, but the price tag is ridiculous.

Running a mainline kernel on a cellphone

keroami — Fri, 30 Oct 2015 12:10:06 +0000

Neo900 runs 4.3-rc7 as we speak.
http://neo900.org
Tons of other cool features in that (upcoming) phone, too.

Running a mainline kernel on a cellphone

jcm — Thu, 29 Oct 2015 22:50:35 +0000

The only way to get to a point where upstream kernels just run on phones is through force. None of the handset vendors has a commercial benefit to devoting cycles to upstreaming code when their competitors are not doing the same, and to think they can be "convinced" is (nice, but) wishful thinking.

Instead, it needs someone like Google to force vendors to do what's in the greater good. Enterprise computing didn't just get where it is either - but in that space there are those who stick to "upstream first" as a rigid requirement that forces others to jump through hoops to upstream code. In the case of Android, Google don't ship the resulting kernel/build directly, but they could make it a requirement of CTS (Compatibility Test Suite) that handset vendors must run in order to have access to the Play Store. Google could do this, but they have little incentive to do so, and my guess is that they never will.

Running a mainline kernel on a cellphone

khim — Thu, 29 Oct 2015 21:18:40 +0000

It's funny that so many wise guys could miss the point so much. Android vendors don't need the mainstream kernel. They just need one kernel where all the features coalesce. If it'll be perpetually extended Linux kernel 3.10 with bazillion extensions - they would be happy.

The only hope here is the fact that Google does not use these kernels on their servers. Which means that this solution will not be accepted by Google. But since this is such an obvious solution... are we sure it'll not be pushed by some other large group of vendors?

Running a mainline kernel on a cellphone

genaro — Thu, 29 Oct 2015 12:58:09 +0000

The association is relevant, as it is only a matter of time before a nasty kernel bug presents on Android devices. As the old kernels drift further from mainline, any effort to bring them up to speed becomes that much more difficult. Stagefright is an easy fix compared to a kernel issue.

Running a mainline kernel on a cellphone

cov — Thu, 29 Oct 2015 11:21:54 +0000

There seems to be some good Snapdragon device upstreaming progress from Rob Clark, Sony, Qualcomm, and Linaro. I hope it continues.

https://plus.google.com/102276447148493441479/posts/amRvp...

Disclaimer: I work for a Qualcomm subsidiary but am writing in a personal capacity, not on their behalf.

Running a mainline kernel on a cellphone

k3ninho — Thu, 29 Oct 2015 10:48:40 +0000

Was there any comment made about newer handsets using chips runnnig ARMv8, and them possibly being configured at startup via ACPI? Would it have divided the room into a fight over DT?

K3n

Running a mainline kernel on a cellphone

Seegras — Thu, 29 Oct 2015 09:24:15 +0000

That is precisely the wrong way. Just do it, and make it easy to participate. Publish HowTos, code, and configs. And then spread it around.

And actually, I would like to run a mainline kernel too, but on a Galaxy Nexus or an Xperia Pro. But I definitely lack the skills and time to do it.

Running a mainline kernel on a cellphone

petur — Thu, 29 Oct 2015 08:36:56 +0000

Sorry but I can't remember ever having been able to load a kernel on my n900 that didn't have TI binary blobs. I found the effort of Nokia and TI to be less than stellar....

Running a mainline kernel on a cellphone

voltagex — Thu, 29 Oct 2015 03:38:02 +0000

For the past couple of years I've been playing with the idea of running mainline on the Nexus 4 - get in touch with me if you're interested.

Running a mainline kernel on a cellphone

ssmith32 — Wed, 28 Oct 2015 22:28:54 +0000

It would be nice, but I think the security argument was undercut by the misleading scare tactic of trying to associate the lack of kernel upgrades with a vulnerability in a user space library (stagefright). The problem of an easily updateable open-source user space doesn't really have a solid solution yet. Installing a mainline kernel may or may not help with that.

Running a mainline kernel on a cellphone

mokki — Wed, 28 Oct 2015 22:04:42 +0000

Nokia (with N9 phone) was pushing for mainline kernel. Nokia used to be so big player that they also convinced Texas Instruments and some other component makers on board to push all needed drivers to mainline. Nokia + TI were both in LWN top kernel contributor company lists for 10 months.
That stopped soon after Microsoft acquisition, but users are still continuing the quest of full mainline support for the N9 phone.

Running a mainline kernel on a cellphone

Jonno — Wed, 28 Oct 2015 19:51:06 +0000

> I don't think Debian includes much support beyond mainline (and backported patches).

Currently Debian stable contains 621 patches (+51078 -9753) on top of 3.16.7-ckt11, of which 110 patches (+1750 -1541) are "bugfix" (mostly backports), 462 patches (+47185 -7608) are "features" (mostly drivers), and 49 patches (+2143 -604) are Debian specific.

While most distribution kernels aren't nearly as bad as most vendor kernels, they aren't really mainline either...